Merc 115 EFI 4 Stroke running rough

[gltrok]

Hi, need some help ! I have a 2005 Merc 115 EFI 4 stroke motor that is running very rough. Started up the first time this year over the weekend and it does not seem to be hitting on all cylinders. Changed plugs and no difference. She ran great last year at the end of the season. I used fuel stabilzer over the Winter. It starts up just fine and idles but very rough above idle. Any help is greatly appreciated. Thanks

 

[Navy Jr.]

Re: Merc 115 EFI 4 Stroke running rough

Might be time to change air and fuel filters. My manual says to check and replace (if necessary) low pressure fuel filter every 100 hours or yearly, and to check and replace high pressure in-line fuel filter every 300 hours. The high pressure filter requires a special tool, and the manual recommends only a factory authorized technician change it.

There are instructions on how to replace the air filter, but the manual doesn't say how often it should be done.

 

[gltrok]

Re: Merc 115 EFI 4 Stroke running rough

Turned out to be a clogged injector.